[vtkusers] Texture Mapping Problem....Please Help !!!!!

[Deepak Roy]

Hello Marc,
   
  Thanks for the reply.
   
  I started working back on this texture issue now, which set aside due to other high priority work.
   
  But when i visualize these surface models, in third party vrml viewers the texture comes out well. Its only in my program that i find these pattern of cracks.
   
  What do you think could be the problem ?
   
  Regards,
   
  Deepak

Marc Cotran <marc at cotran.ca> wrote:
  Hi Deepak,

I had experienced similar results before and concluded that the polygon 
normals were the culprit. I would suggest visualizing the polydata mesh 
in wireframe to see if some of your polygons are oriented opposite to 
the others. I am not sure this is what you're dealing with, but it might 
explain your problem. As for a potential solution... I am at a loss.

Should you figure out the problem, I'd love to know the solution.

HTH,

Marc

Deepak Roy wrote:
> 
> Hello everyone,
> 
> I have had a hard time trying to fix this texture display problem.
> 
> Attached is a part of the texture image i am using for the human body. 
> I have removed the face and other parts due to some identity revealment 
> problems.
> 
> But the image gives an idea of the problem i am facing. Look at the 
> image and you will see the cracks on the texture.
> 
> when i visualize the same model in some other standard graphics software 
> like Rapid Forms, the texture shows up with out any cracks.
> 
> I have tried all the possible options with vtkTexture but still i could 
> not fix the problem.
> 
> /"Can anyone explain this phenomenon ? "/
> 
> One more point to note, which i also mentioned in my previous posting to 
> the mailing list, is that exactly the same pattern of cracks appear in 
> every model i load.
> 
> I suspect, it is got to do with clamping or interpolation.
> 
> Please help me fix this problem.
> 
> Thanks in Advance.
> 
> Regards,
> 
> Deepak Roy
> 
> 
> 
> 
> Yahoo! Music Unlimited - Access over 1 million songs. Try it free. 
> 
> 
> ------------------------------------------------------------------------
> 
> Subject:
> Texture Mapping Problem....Please Help !!!!!
> From:
> Deepak Roy 
> Date:
> Fri, 14 Oct 2005 15:42:33 -0700 (PDT)
> To:
> vtkusers at vtk.org
> 
> To:
> vtkusers at vtk.org
> 
> 
> Hi,
> 
> I am trying to displaying a 3D surface of a human body with texture, all 
> captured from a 3D scan. I am using vtkTecture to assosciate the actor 
> with the texture.
> 
> The problem is:
> 
> I see a pattern of cracks on surface when displayed with texture. These 
> cracks are not present in the basic geometry of the model as the surface 
> when visualised without texture appears fine and smooth. I am 100% sure 
> that this is the problem with texture mapping.
> 
> One more thing that was wierd was that i see more or less the same 
> pattern of tracks on each model i display.
> 
> Could anyone explain the reason why this is happening?
> 
> I guess the problem is with the edge clamping used while mapping the 
> texture. But vtkTexture does not give me any control on how to change 
> these parameters.
> 
> How can i change the these parameters and control the way texture 
> mapping is done. Is there an easy way to do this?
> 
> Thanks in Advance.
> 
> Regards
> 
> Deepak
> 
> 
> Yahoo! Music Unlimited - Access over 1 million songs. Try it free. 
> 
> 
> ------------------------------------------------------------------------
> 
> 
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> 
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